Feed dog cover for zigzag and like attachments



Nov. 10, 1959 s. P. CALDWELL 2, 2

FEED DOG COVER FOR ZIGZAG AND LIKE ATTACHMENTS Filed April 1, 1958 2 Sheets-Sheet 1 BYqMVW ATTORNEYS Nov. 10, 1959 s. P. CALDWELL 2,911,929

FEED DOG COVER FOR ZIGZAG AND LIKE ATTACHMENTS Filed April 1, 1958 2 Sheets-Sheet 2 ATTORNEY United States Patent 9 FEED DOG COVER FOR ZIGZAG AND LIKE ATTACHMENTS Samuel P. Caldwell, Hamden, Conm, assignor to The Greist Manufacturing Company, New Haven, Conn., a corporation of Connecticut Application April 1, 1958, Serial No. 725,622

8 Claims. (Cl. 112- 160) This invention relates to a feed dog cover for zigzag machines or the like wherein an attachment is employed to move the cloth laterally during the stitching operation so that a zigzag or decorative stitch results. 1

With such an attachment the cloth is moved forwardly by the usual feed dog of the sewing machine and usually moved laterally by the cloth foot which is a part of the attachment and which is arranged to move laterally with respect to the attachment and with respect to the line of stitching or the direction of feed of the material. As is understood, both the forward feed of the material and the lateral or transverse movement thereof must be effected when the needle is out of the cloth. In some types of machines there is some lag between the time that the needle leaves the cloth and the feed dog rises above the throat plate to engage the cloth and feed it forwardly. However, in other machines the feed dog follows the needle closely and rises above the surface of the throat plate to engage the cloth just as the needle is leaving the cloth. When a zigzag or decorative stitch attachment is employed with such a machine, some difllculty is encountered as the lateral movement of the cloth foot on the attachment tends to move the cloth laterally at the same time that it is engaged by the feed dog with unsatisfactory results.

In accordance with the present invention means are provided to gain time between the disengagement of the cloth by the needle and the engagement of the cloth by the forwardly moving feed dog. That is to say, provision is made for holding the cloth out of contact with the rising feed dog so that the laterally moving cloth-engaging foot on the attachment may have opportunity to perform its function after the needle is out of the cloth and before the latter is engaged by the feed dog.

One object of the present invention is to provide means for attachment to the usual household sewing machine wherein engagement between the feed dog and the material being used is delayed until an appropriate time after the needle leaves the material.

Another object of the invention is to provide means for holding the cloth or material upwardly out of engagement with the usual feed dog of a sewing machine during the initial part of the movement of the latter whereby the cloth may be moved laterally before being engaged by the feed dog.

A still further object of the invention is to provide an attachment for the usual household sewing machine which will be actuated by the rising movement of the feed dog and which will hold the cloth out of engagement with the feed dog until the sewing needle has been raised out of the cloth.

Still another object of the invention is to provide means to be used in connection with a decorative stitch or zigzag attachment for the usual household sewing machine which will enable the cloth to be moved laterally between the time at which the needle leaves the cloth and the time at which the cloth is engaged by the moving feed dog ice of the sewing machine, this being eifected by holding the cloth out of engagement with the upwardly moving feed dogat the beginning of the forward stroke of the latter.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter dsecribed and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of a feed dog cover embodying my invention;

Fig. 2 is a top plan view of the feed dog cover as applied to the bed plate of a sewing machine;

Fig. 3 is a sectional view on line 3-3 of Fig. 2;

Fig. 4 is an enlarged sectional View on line 44 of Fig. 2;

Fig. 5 is a sectional view similar to Fig. 4, showing the parts in another position;

Fig. 6 is a view similar to Figs. 4 and 5, showing the parts in an advanced position of the feed dog with respect to Fig. 5;

Fig. 7 is a top plan View of a modified form of my invention;

Fig. 8 is an enlarged sectional View on line 88 of Fig. 7; and

Figs. 9 and 10 are sectional views similar to Fig. 8 but showing the parts in different advanced positions of the feed dog.

Illustrating a preferred embodiment of the invention there is shown in Figs. 1 and 2 of the drawings a bed plate 10, the throat plate 11 and the feed dog 12, all of which are of the usual construction, the throat plate being provided with an opening 13 through which the feed dog rises and moves forwardly to effect forward feeding of the cloth or material being sewed. Also shown more or less diagrammatically in Fig. '1 are the presser bar 14 and the needle bar 15 carrying the sewing needle 16. All of these parts are of the usual construction as is also an attachment shown in dotted lines and designated generally by the numeral 17 which is provided with a clothengaging foot 18 designed to move the cloth laterally when zigzag or decorative stitching is desired.

As shown in Fig. 1, the needle 16 is in a lower position and the feed dog 12 lies below the upper surface of the throat plate 11. In the operation of the machine the needle is moved upwardly so as to clear the cloth or material and at the same time the feed dog is moved upwardly to engage the cloth and then forwardly to effect a forward feeding thereof. It is contemplated by the present invention to provide means for preventing engagement of the feed dog with the cloth or material (upon its upward movement) until the cloth-engaging foot of the attachment has had an opportunity to move the cloth laterally.

As illustrated in Figs. 1 to 5, this is effected by providing a cover or partial cover for the feed dog in the form of a flexible or spring plate 20 which may be secured to the bed plate 10 of the sewing machine by screws 21,

. these screws being inserted through enlarged openings 22 and 24. It will be noted that the edge of the stepped portion 23 overlies to some extent the rear portion of the teeth 25 of the feed dog, and the edge 24 of the cover 20 overlies the rear portion of the teeth 26 so that, when the feed dog rises from its lower position shown in Fig. 1, these teeth of the feed dog will engage the cover member 20 and raise it upwardly at its free end, that is, the end 3 opposite that which at attached to the bed plate by the screws 21.

As the cloth or material is fed over the cover 20, the raising of the cover adjacent the feed dog will also raise the cloth or material and delay the engagement of the exposed teeth of the feed dog with the cloth. So soon, however, as the feed dog moves forwardly a short distance, the teeth 25 and 26 will be released from the stepped portions 23 and 24 of the cover 20 and permit the latter to drop downwardly by its own resilience so that the teeth of the feed dog exposed in the opening 13 of the throat plate will engage the cloth and feed it forwardly. This will provide the necessary lag between the time that the needle leaves the cloth and the time that the feed dog engages the cloth to permit lateral movement of the cloth by the zigzag or decorative stitch attachment. While the efiect of a small part of the forward movement of the feed dog will be lost, sufficient movement will remain to efiect the necessary feed of the material and interference will be prevented between the effort of the feed dog to move the material forwardly and the elfort of the cloth foot of the attachment to move the material laterally.

It is understood that as the cover member 20 is quite flexible, being made of thin steel or the like, it will normally lie flatly upon the bed plate 10 and throat plate 11, as shown in full lines in Fig. 3, until moved upwardly by the throat plate, as shown in dotted lines in this figure. Upon its release by the feed dog, it will immediately return to its normal position.

The operation of the device is shown more especially in Figs. 4, 5 and 6 wherein the cloth or material is indicated in dotted lines at 27. As shown in full lines in Fig. 4, the needle is in a lower position as is also the feed dog which is below the upper surface of the throat plate and is not in engagement with the cover 20. The position of the parts just as the needle leaves the material is shown in dotted lines in this figure where it will be seen that the rear tooth 28 of the series of teeth 26 of the feed dog is barely in engagement with the lower surface of the cover 20 but has not yet moved upwardly to a suflicient extent to raise the cover, it being understood that the initial movement of the feed dog will be upwardly from its full-line position.

As shown in Fig. 5, the feed dog has continued to move upwardly and the engagement of the tooth 28 with the stepped portion 24 and likewise the engagement of a tooth of the series 25 with the stepped portion 23 has raised the plate 20 upwardly a slight distance away from the throat plate 11 and likewise has raised the material or cloth 27 so that the teeth of the feed dog are not yet in engagement with the material. It would be appreciated, however, that, if the cover 20 were not holding the material upwardly, the teeth of the feed dog would be in engagement with the cloth as these teeth are above the upper surface of the throat plate 11.

From the position shown in Fig. 5, the feed dog moves forwardly until the teeth thereof move out of engagement with the cover, as shown in Fig. 6, and the cover descends due to its own resilience to a position where it is again in contact with the throat plate which permits the teeth of the feed dog to engage the cloth over the opening 13 in the throat plate and effect forward feeding of the cloth.

Between the time that the needle leaves the cloth, as shown in dotted lines in Fig. 4, and the time that the feed dog disengages the cover 20 and forward feeding of the material starts, as shown in Fig. 6, the cloth-engaging foot of the attachment has an opportunity to move the cloth laterally without interference from the teeth of the feed dog.

Another means of effecting a comparable result is shown in Figs. 7 to 10 of the drawings wherein a throat plate 11 is secured to the bed plate 10. In this instance the heads of the screws 30 which attach the throat plate to-the bed plate are mounted in countersunk recesses 31 of the throat plate so as to permit the latter to have slight upward play although it will normally lie flatly upon the bed plate due to its own weight, as shown in Fig. 8.

In this instance the opening 13 of the throat plate is slightly modified with respect to the opening 13 of the throat plate 11, as shown in Fig. 2, in that it is provided with stepped portions 32 and 33 which overlie the rear teeth of the feed dog when the latter is in its rearmost position from which is rises upwardly in its movement. Thus, when the feed dog is moved upwardly, the rear teeth thereof will engage the edges 32 and 33 of the opening of the feed plate and raise the latter slightly as permitted by the heads of the screws 30 and as shown in Fig. 9.

The operation of this form of my invention is shown in Figs. 8 and 9 wherein the cloth or material is indicated at 27. The lowermost position of the feed dog is shown in Fig. 8 and, as the feed dog rises from this position, the rear teeth thereof will engage the throat plate 11, as shown in Fig. 9, and carry this plate upwardly so as to rise the cloth or material 27 and prevent the teeth of the feed dog from engaging the cloth. However, when the feed dog is moved forwardly, as shown in Fig. 10, the teeth thereof are disengaged from the throat plate and permit the latter to drop by its own weight to its normal position. At this time the teeth of the feed dog will engage the material and elfect forward feeding thereof. However, the material has been held out of engagement with the feed dog for a sufiicient length of time so that the needle may be disengaged from the cloth and the latter fed laterally by the cloth-engaging foot of the attachment.

While I have shown and described some embodiments of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. In a sewing machine having a bed, a movable feed dog mounted below the bed to eifect forward movement of the material being sewed, and a cloth-engaging foot to effect lateral movement of the material, a member on the bed over which the material travels, and means movably attaching said member to the bed for up-and-down movement relatively thereto and for engagement by the feed dog whereby said member is moved away from the bed upon upward movement of the feed dog, said member having an edge portion overlying the rear portion of the feed dog when the latter is in its rear position but leaving the remainder of the feed dog exposed.

2. In a sewing machine having a bed, a movable feed dog mounted below the bed to effect forward movement of the material being sewed, and a cloth-engaging foot to effect lateral movement of the material, means to prevent engagement of the feed dog with the material during the initial part of its feeding stroke, said means comprising a member attached to the bed for up-and-down movement relatively thereto, and means attaching said member to the bed in position to be engaged by the feed dog to be moved upwardly thereby.

3. An attachment for a sewing machine having a bed and a movable toothed feed dog to effect forward movement of the material being sewed, said attachment comprising a plate member attached to the bed for movement theretoward and away therefrom over which member the material passes, and means attaching said member to the bed in position to be engaged and moved upwardly upon upward movement of the feed dog and released to return to its original position upon forward movement of the feed dog.

4. An attachment for a sewing machine having a bed and a movable toothed feed dog to effect forward movement of the material being sewed, said attachment comprising a plate member attached to the bed for movement theretoward and away therefrom over which member the material passes, and means attaching said member to the bed in position to be engaged and moved upwardly upon upward movement of the feed dog and released to return to its original position upon forward movement of the feed dog, said member having an opening through which the feed dog moves and an edge of said opening being in position to be engaged by the teeth of the feed dog.

5. An attachment for a sewing machine having a bed and a movable toothed feed dog to effect forward movement of the material being sewed, said attachment comprising a plate member attached to the bed for movement theretoward and away therefrom over which member the material passes, means attaching said member to the bed in position to be engaged and moved upwardly upon upward movement of the feed dog and released to return to its original position upon forward movement of the feed dog, said member comprising a throat plate loosely secured to the bed and having an opening through which the feed dog moves to engage the material, and an edge of said opening being in position to be engaged by the feed dog upon upward movement of the latter to hold the material temporarily out of engagement with the feed dog.

6. An attachment for a sewing machine having a bed and a movable toothed feed dog to effect forward movement of the material being sewed, said attachment comprising a plate member attached to the bed for move ment theretoward and away therefrom over which member the material passes, means attaching said member to the bed in position to be engaged and moved up Wardly upon upward movement of the feed dog and released to return to its original position upon forward movement of the feed dog, said member comprising a flexible plate secured adjacent one of its ends to the bed, the other end extending over said feed dog and having an opening through which the latter engages the material, and an edge of said opening being in position to be engaged and moved by the feed dog upon an upward movement of the latter to hold the material away from the feed dog.

7. An attachment for a sewing machine having a bed and a movable toothed feed dog to effect forward movement of the material being sewed, said attachment comprising a plate member attached to the bed for move ment theretoward and away therefrom over which member the material passes, means attaching said member to the bed in position to be engaged and moved upwardly upon upward movement of the feed dog and released to return to its original position upon forward movement of the feed dog, said member comprising a flexible plate secured adjacent one of its ends to the bed, the other end extending over said feed dog and having an opening through which the latter engages the material, and an edge of said opening overlapping a part of the path of the feed dog to be in position to be engaged and moved by the feed dog upon an upward movement of the latter to hold the material away from the feed dog and to be released after initial forward movementv of the feed dog to permit engagement of the latter with the material during he remainder of its movement.

8. An attachment for a sewing machine having a bed and a feed dog movably mounted below the bed to engage and feed the material forwardly, said attachment comprising a platelike member, means for attaching said member loosely to the bed to permit upward movement of the member, said member having an opening through which the feed dog engages the material, and a part of said member adjacent an edge of said opening being disposed in position to be engaged by the rear edge of the feed dog upon upward movement of the latter and to be released upon forward movement of the feed dog, and the material passing over said member in its passage through the machine.

References Cited in the file of this patent UNITED STATES PATENTS 42,110 Redmond Mar. 29, 1864 445,468 Hanna Ian. 27, 1891 493,496 Hall Mar. 14, 1893 2,820,425 Enos Jan. 21, 1958 2,823,632 Garasimowicz Feb. 18, 1958 

